1,721,215 research outputs found

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis

    Dispelling the Myths Behind First-author Citation Counts

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    We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more sophisticated methods

    Author Index

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    Thio- and seleno-ether complexes with Group 4 tetrahalides and tin tetrachloride: preparation and use in CVD for metal chalcogenide films

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    Reaction of TiCl4 or ZrI4 with the soft, neutral o-C6H4(CH2EMe)2 (E = S or Se) in anhydrous CH2Cl2 (or toluene) yields the distorted octahedral chelate complexes [MX4{o-C6H4(CH2EMe)2}]. Using Et2Se gives [MX4(Et2Se)2] (M = Zr, X = Cl or I; M = Hf, X = I). The Sn(IV) analogues, [SnCl4{o-C6H4(CH2EMe)2}] and [SnCl4(Et2Se)2] were obtained similarly. These complexes have been characterised spectroscopically and analytically, and crystal structures of trans-[SnCl4(Et2Se)2] and some selenonium salts derived as minor by-products from the parent Group 4 complexes are described. The neutral chalcogenoether complexes have been evaluated as single source precursors to ME2/ME thin films via LPCVD. [TiCl4{o-C6H4(CH2EMe)2}] leads to the deposition of air and moisture stable TiE2 films (with no residual Cl). Coverage of the substrate is uniform with platelet growth perpendicular to the surface. The heavier Zr(IV) species do not lead to significant ZrE2 deposition. On the other hand, LPCVD of [SnCl4{o-C6H4(CH2SMe)2}] leads to deposition of SnS2 at lower temperatures and SnS at higher temperatures, while [SnCl4{o-C6H4(CH2SeMe)2}] gives rather uneven coatings of SnSe2. The Et2Se derivative, [SnCl4(Et2Se)2] leads to uniform deposition of SnSe2 with growth perpendicular to the substrate surface. The SnE2/SnE films are stable indefinitely to air and moisture. The generation of TiS2, SnS2 and SnS in this way are very rare examples of metal sulfide deposition from C–S bond fission within a thioether complex

    Vanadium selenoether and selenolate complexes, potential single-source precursors for CVD of VSe2 thin films

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    Reactions of VCl4 with one mol equiv. of L–L (L–L = MeSe(CH2)2SeMe, MeSe(CH2)3SeMe, nBuSe(CH2)2SenBu) in anhydrous CH2Cl2 solution at room temperature give [VCl4(L–L)] as very moisture-sensitive dark purple solids. Using VCl4 and excess selenoether in gently refluxing CH2Cl2 leads to reduction to [VCl3(L–L)] (L–L as above and o-C6H4(CH2SeMe)2), while VCl4 reacts with excess SeMe2 at room temperature to give [VCl3(SeMe2)2]. All new complexes were characterised by microanalysis, IR and UV/visible spectroscopy and magnetic measurements. Reaction of [(Cp)2VCl2] with two mol equiv. of LiSetBu in anhydrous thf gives the VIV selenolate complex [(Cp)2V(SetBu)2] as a very moisture-sensitive brown solid. The new complexes have been investigated as possible reagents for deposition of vanadium selenide. While low pressure chemical vapour deposition (LPCVD) experiments showed that the diselenoether complexes were not sufficiently volatile for VSe2 deposition, [VCl3(SeMe2)2] gives very thin deposits of VSe2. LPCVD studies on [(Cp)2V(SetBu)2] at 600 °C produce thicker black films of VSe2. In all cases EDX measurements show that the films are Se deficient

    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used

    Evaluation of group 4 metal bis-cyclopentadienyl complexes with selenolate and tellurolate ligands for CVD of ME2Films (E = Se or Te)

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    The selenolate and tellurolate complexes [Cp2M(SeR)2] (M = Ti, Zr, or Hf; R = Me or But) and [Cp2M(TeBut)2] (M = Zr or Hf) have been prepared and characterized by 1H, 13C{1H}, 77Se{1H} and 125Te{1H} NMR spectroscopy and microanalysis. Crystal structures of representative examples are reported, together with the structure of the oxo-bridged species [{Cp2Zr(SeMe)}2(?-O)] formed by partial hydrolysis. Trends in the NMR parameters are discussed. These molecular [Cp2M(SeBut)2] complexes are shown to be suitable as precursors for the single source LPCVD of intensely colored MSe2 thin films for each of the Group 4 elements, confirmed by SEM/EDX and PXD. These are the first examples of single source CVD of ZrSe2 and HfSe2 thin films. The corresponding [Cp2M(TeBut)2] species (M = Zr or Hf) deposit elemental Te under similar LPCVD conditions
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